Coupling the motive force of an engine with a limited range of revolutions per minute and more especially a limited range of torque to a piece of equipment that needs to have a wide range of operating speeds requires a method of connecting the engine to the equipment with some method of varying the ratio of speeds between the two.
The most common method uses combinations of gears and means of selecting the gears needed to match the engine to the equipment. Other methods include hydraulic systems with variable pumps and motors. Recent methods in the automotive industry include using belts on adjustable pulleys. A single torque converter with a lock-up feature is most commonly used in today's vehicles with automatic transmissions in an attempt to provide a more continuous change of ratio.
Gear sets do not always correctly match the differential speeds needed and with the more gears used to solve this issue, more weight and other problems arise. Hydraulic systems waste energy at high speeds. Belt systems can not deliver higher horse power with our significant wear. A single lock-up torque converter does not provide a wide enough ratio to eliminate the need of gear sets coupled to the converter.
It is therefore an object of the invention to provide an arrangement of torque converters in series with each other to provide the torque multiplication needed by a particular vehicle.
It is another object of the invention to provide the housing to support the bearing plates between each converter in series as to support the needs of a torque converter such as fluid flow for the operation of the converter and control of the lock-up function.
It is another object of the invention to use the lock-up feature of the torque converters to create a final drive ratio of one to one with minimal loss of energy.
It is another object of the invention to use the effect of a torque converter providing a two to one torque multiplication ratio output at stall speed, to be coupled in series to a second converter and thus have a four to one ratio and as needed to continue this configuration for an eight to one ratio with three converters and so on.